It is known that Greenland Eskimos rarely suffer from atherosclerotic cardiovascular diseases. This fact has been attributed to the consumption of high amounts of fish oil. The active ingredients in fish oil are (all-Z)-5,8,11,14,17-eicosapentaenoic acid (hereinafter EPA) and 22:6.omega.3-docosahexaenoic acid (hereinafter DHA). EPA and DHA are known to be precursors in the biosynthesis of the prostaglandin PGE.sub.3.
It is disclosed in British Pat. Nos. 1,604,554 and 2,033,745 that EPA can be used to treat effectively, or provide effective prophylaxis against, thrombo-embolic conditions such as myocardial infarctions, strokes, or deep vein thrombosis during surgical operations. They disclose the extraction of EPA from fish oil, such as cod liver oil or menhaden oil. The EPA may be administered by replacing butter or ordinary margarine by a special margarine formulated so that in normal usage the recipient would receive the required amount of the EPA.
This process has not achieved widespread attention, despite the fact that it uses a natural substance which can readily be incorporated into the daily diet. One reason may be due to the difficulty of efficiently separating EPA from natural fish oils to obtain a pure product at reasonable cost. Another reason may be that the effects of administration of EPA are not as dramatic as anticipated.